$.extend({ 
  
/**  
 1. 设置cookie的值，把name变量的值设为value    
example $.cookie(’name’, ‘value’); 
 2.新建一个cookie 包括有效期 路径 域名等 
example $.cookie(’name’, ‘value’, {expires: 7, path: ‘/’, domain: ‘jquery.com’, secure: true}); 
3.新建cookie 
example $.cookie(’name’, ‘value’); 
4.删除一个cookie 
example $.cookie(’name’, null); 
5.取一个cookie(name)值给myvar 
var account= $.cookie('name'); 
**/
    cookie: function(name, value, options) { 
        if (typeof value != 'undefined') { // name and value given, set cookie 
            options = options || {}; 
            if (value === null) { 
                value = ''; 
                options.expires = -1; 
            } 
            var expires = ''; 
            if (options.expires && (typeof options.expires == 'number' || options.expires.toUTCString)) { 
                var date; 
                if (typeof options.expires == 'number') { 
                    date = new Date(); 
                    date.setTime(date.getTime() + (options.expires * 24 * 60 * 60 * 1000)); 
                } else { 
                    date = options.expires; 
                } 
                expires = '; expires=' + date.toUTCString(); // use expires attribute, max-age is not supported by IE 
            } 
            var path = options.path ? '; path=' + options.path : ''; 
            var domain = options.domain ? '; domain=' + options.domain : ''; 
            var secure = options.secure ? '; secure' : ''; 
            document.cookie = [name, '=', encodeURIComponent(value), expires, path, domain, secure].join(''); 
        } else { // only name given, get cookie 
            var cookieValue = null; 
            if (document.cookie && document.cookie != '') { 
                var cookies = document.cookie.split(';'); 
                for (var i = 0; i < cookies.length; i++) { 
                    var cookie = jQuery.trim(cookies[i]); 
                    // Does this cookie string begin with the name we want? 
                    if (cookie.substring(0, name.length + 1) == (name + '=')) { 
                        cookieValue = decodeURIComponent(cookie.substring(name.length + 1)); 
                        break; 
                    } 
                } 
            } 
            return cookieValue; 
        } 
    } 
  
});
